JPH0545247U - Bearing support structure for the mission case - Google Patents

Abstract

(57) [Summary] [Purpose] To extend the life of the bearing by making it possible to support the bearing with approximately even supporting stress around its axis. [Structure] A bearing mounting hole 16 is integrally formed on an aluminum die-cast case body 14, and screw pilot holes 18 for mounting a tapping screw 17 are integrally formed on a plurality of peripheral portions of the bearing mounting hole 16. The outer peripheral surface of the head of the tapping screw 17 screwed into the screw hole 18 is supported by the outer peripheral surface of the bearing 15 fitted in the bearing mounting hole 16.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a bearing support structure for a mission case made of aluminum die casting.

[0002]

[Prior Art]

 Conventionally, the support of a bearing in this type of mission case has been carried out by inserting the bearing into a bearing mounting annulus of a case that has been finished for the purpose of centering the mounting of the bearing and the like.

[0003]

[Problems to be solved by the device]

 By the way, in recent years, in order to rationalize the manufacturing process, it has been proposed to directly insert the bearing without finishing the bearing mounting ann formed beforehand in the casting process. However, as described above, when the bearing is simply inserted into the bearing mounting hole, the bearing mounting hole is formed into a tapered surface with a draft so that the bearing can be pulled out. Of the bearing is apt to be biased to a specific location.Therefore, an unbalanced load is applied to a specific location of the bearing, wear at the specific location becomes more significant than others, and the bearing life is shortened. It was The present invention has been made in view of the above circumstances, and a bearing for a mission case capable of extending the life of the bearing by allowing the bearing to be supported with a substantially even supporting stress around its axis. The purpose is to provide a support structure.

[0004]

[Means for Solving the Problems]

 In order to achieve the above-mentioned object, the bearing support structure of the mission case according to the present invention has a case body made of aluminum die casting integrally formed with a bearing mounting ann. A tapped hole for tapping screw mounting is formed in one piece, and the outer peripheral surface of the head of the tapping screw screwed into this tapped hole supports the outer peripheral surface of the bearing fitted to the bearing mounting annulus. The feature is that it is present. The actions and effects of this characteristic configuration are as follows.

[0005]

[Action]

 That is, tapping screws are screwed into screw holes formed in a plurality of peripheral portions of the bearing mounting annulus formed on the case main body, so that the outer circumference of the bearing previously mounted in the bearing mounting ann is mounted. The surface and the outer peripheral edge of the head of the tapping screw can be brought into contact with each other, and this contact allows the bearing to be supported around its axis only while avoiding being supported only at a specific position. Therefore, the supporting stress can be applied to the outer peripheral portion of the bearing substantially evenly around its axis.

[0006]

[Effect of the device]

 Therefore, the bearing stress can be applied to the outer peripheral portion of the bearing almost evenly around its axis, and it is possible to suppress wear that is unevenly distributed to specific parts of the bearing, and to use the bearing for a long life and Since it is not necessary to accurately finish the bearing mounting annulus of the case body, the manufacturing cost can be reduced.

[0007]

【Example】

 Embodiments of the present invention will be described below with reference to the drawings. FIG. 4 shows a walk-behind management machine including the mission case 3 according to the present invention. In this walk-behind management machine, an engine 2 is mounted on a body frame 1, a vertically long mission case 3 is provided behind the engine 2, and a pair of left and right traveling wheels 4, 4 are provided below the mission case 3. And a handle rod 5 is provided rearward from the upper portion of the mission case 3, and a rotary tiller 7 is attached to a hitch 6 at the rear of the mission case 3.

As shown in FIG. 5, the hitch 6 can change its mounting position up and down with respect to the mission case 3, and the mounting position can be appropriately changed according to the working device mounted on the hitch 6. Change and tighten the bolts.

As shown in FIG. 6, the rotary pawl 10 of the rotary tiller 7 that is transmitted by the sub-chain case 9 that is interlocked with the output shaft 8 on the upper part of the transmission case 3 is connected to the rotary shaft 11. The through holes formed at the four corners of the claw mounting flange 12 and the long holes 10a and 10b formed at the base of the rotary claw 10 are fixedly connected by bolts. The claw mounting flange 12 is provided with a large number of through holes so that the claws can be mounted at different mounting positions according to the types of various rotary claws, the claw lengths, and the like.

Next, a structure for supporting the axle 13 for the traveling wheels 4 and 4 and the bearing for pivotally supporting the output shaft 8 will be described. As shown in FIG. 1, the mission case 3 is made up of case bodies 14 made of aluminum die-cast in half and connected by bolts, and supports the axle 13 and the output shaft 8. For this reason, bearing mounting cavities 16 for fitting and mounting ball bearings 15 as bearings are formed and provided at the respective supporting points. As shown in FIGS. 1 to 3, screw holes 18 for inserting tapping screws 17, which will be described later, are formed in the case body 14 at three locations in the vicinity of the outer periphery of the bearing mounting ann 16. is doing. These screw holes 18 are formed at equal intervals along the outer circumference of the bearing mounting ann 16.

As shown in FIGS. 1 to 3, when the ball bearing 15 is fitted and mounted in the bearing mounting ann 16 and the tapping screws 17 are screwed into the screw pilot holes 18 ,. The outer peripheral edge 17a of the head portion 17A of 17 contacts the outer peripheral surface of the outer race 15A of the ball bearing 15. Therefore, the outer race 15A of the ball bearing 15 is abutted on the outer peripheral surface of the case body 14 with the tapping screws 17 on the outer side of the case body 14 and the inner side of the case body 14 with bearings. It is supported in a state in which the position of the annulus 16 is abutted against the inner peripheral surface of the annulus 16 and is regulated. The tapping screws 17 are screwed into the screw holes 18 so that the centering of the ball bearing 15 does not deviate and the misalignment is corrected.

The present invention can be applied to a device that uses a bush as a bearing, and the bearing mounting hole may be a bottomed hole or a through hole. Further, the number of screw pilot holes formed in the vicinity of the outer periphery of one bearing mounting hole may be two or more, and the number thereof can be set arbitrarily.

It should be noted that reference numerals are added to the claims of the utility model for convenience of comparison with the drawings, but the invention is not limited to the configurations of the accompanying drawings by the entry.

[Brief description of drawings]

FIG. 1 is a vertical sectional front view showing a bearing support structure of a mission case.

FIG. 2 is an enlarged cross-sectional view showing a bearing support structure.

FIG. 3 is a vertical sectional side view showing a bearing support structure.

FIG. 4 is an overall side view showing a walk-behind management machine.

FIG. 5 is a side view showing how the hitch is attached to the mission case.

FIG. 6 is a side view showing a mounting structure of rotary pawls to a rotary shaft.

[Explanation of symbols]

 14 Case body 15 Bearing 16 Bearing mounting hole 17 Tapping screw 18 Screw pilot hole

Claims (1)

[Scope of utility model registration request] 1. A case body (1) made of aluminum die casting.
4), the bearing mounting hole (16) is integrally formed, and tapped holes (18) for mounting the tapping screw (17) are integrally formed at a plurality of circumferential portions of the bearing mounting hole (16), At the outer peripheral edge of the head of the tapping screw (17) screwed into the screw hole (18), the bearing mounting hole (1
6) A bearing support structure for a mission case, the outer peripheral surface of which is supported by contact with a bearing (15) fitted in 6).